Rotary compressors having the following elements have been known: a cylinder including a cylinder chamber; a piston accommodated in the cylinder chamber and configured to rotate eccentrically; a blade integrally formed with the piston to separate the cylinder chamber into a low-pressure chamber and a high-pressure chamber; and a pair of bushes which hold the blade in such a manner that allows the blade to swing. In such a rotary compressor, the piston rotates eccentrically and changes the capacities of the low- and high-pressure chambers in the cylinder, thereby compressing the refrigerant (see, e.g., Japanese Patent No. 3155895).